First 24 Hrs with a UVB-UVA lamp

Recently had a very in depth conversation with @dbrn32 about adding a UV light
to the grow mix. I was able to obtain an AgroMax Pure UV T5 Florescent and my plan was to pair it with my new-ish HLG LED light. Asked a few pro guys well known for their meaty
grows and got the answer I needed.

Well, a whole 24hrs into ownership and exposure to UVB and UVA rays and my buds look about 33% more sugar coated. They weren’t this icy two days ago that’s for sure.
The only down side is my fan leaves looked more droopy than normal. They came back to full life after their dark period but I’ll keep an eye out this time. I let the light on for the
entire 12 hour light cycle. This light is pretty strong so I’ll run it about half that time today.

@dbrn32 @monkman @merlin44 @Hellraiser @Covertgrower


I have noticed a difference in tric production from just adding the hlguva30 bars to my rooms. Seens twice the trics on the buds and it was alot tastier than my last harvest. What do uvb lights do diff from uva. I heard uvb is bad for plants and causes more issues with mold and whatnots using uvb lights.

Looking good , how far into flower ? Supplemental light HLG is completely out :frowning:

On the contrary, UVB kills mold and fungus spores, increases terp profiles and causes the plant to produce more resins. Outdoor growers have their plants blasted with UVB, the higher the elevation the more UVB it gets.

Check out Dr. Bruce Bugbee’s videos on cannabis and the UV spectrum.


I’m at the end of week 7.
The bulb and fixture were less than $85 shipped to my door. The bulb puts out 75% uvb and 25% uva wavelengths at 47watts.

I really couldn’t ask for a better supplemental uv light even at double the price.

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Did you get the 2 or 4 foot bulb?Where do you put them and what kind of fixture do you need@PhillyRock

great job Philly, nice to know. i’ll pay more attention this grow to the difference in trichs between the LEC and the QB/

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Sounds great , i just need to read more and understand what’s up

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Looking good!

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While looking for information about UV effects on cannabis I found a series by Dr. Bruce Bugbee of University of Utah. He’s one of a handful of pHD’s on the cutting edge of horticultural lighting and plant biology. He’s got about a half dozen videos on the f-UTube (I loath the politics of big tech and social media) and the information contained within those videos are quite eye opening. I was incredibly shocked how much I learned in such a short period if time.

If you have some free time check them out yourself. It’s very enriching data.

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I got the 2ft bulb and fixture.
The fixture I bought was a high reflective 22.62 self contained ballast from ‘lighting solutions’ for $39.79 and ordered the bulb from HTG for $21 plus shipping.

I hung the fixture right in parallel with my HLG 260. They are both the same length so it was easy.

How far away from the canopy? And for how long per day? I just ordered two of them and can’t find enough information on exposure time and distance. Thanks.